A multilayer ceramic capacitor (MLCC), a multilayer chip electronic component, is a capacitor in the form of a chip mounted on a substrate of electronic products such as an image display device, such as a liquid crystal display (LCD), a plasma display panel (PDP), and the like, a computer, a personal digital assistant (PDA), a cellular phone, and the like, serving to charge and discharge electricity.
An MLCC has the advantages of being small, securing high capacitance, and being easily mounted, so it may be used as a component of various electronic devices.
The MLCC may have a structure in which a plurality of dielectric layers, and internal electrodes having different polarities, interposed between the dielectric layers, are alternately stacked.
Since the dielectric layer has piezoelectric and piezoresistive properties, when a direct current (DC) or alternating current (AC) voltage is applied to an MLCC, a piezoelectric phenomenon may occur between the internal electrodes, resulting in vibrations.
As the vibrations are transmitted to a board on which the MLCC is mounted through an external electrode of a MLCC, the entirety of the board becomes an acoustic reflective surface, so vibrational sounds, becoming noise, may be generated.
The vibration sound may correspond to an audible frequency in the range of 20 Hz to 20,000 Hz, which may be unpleasant for listeners, and the vibration sound is referred to as acoustic noise.
Recently, a low noise design of an electronic product has become important, and acoustic noise generated in an MLCC is becoming an issue. In detail, a reduction in acoustic noise occurring in an electronic product having a voice communication function, such as a smartphone has been required.